Tax season comes in April for most of us, but Congress has the peculiar habit of doing its tax business every December. Each year (sometimes ahead of a tax year, and sometimes after the fact) policymakers consider a so-called “extenders package” of tax provisions that expire on a regular basis. The reason for such an arrangement is to generate a “must-pass” legislative tax vehicle ahead of the Christmas break. An extenders package is a mixture of tax relief for businesses and for families, with priorities for Republicans and Democrats alike. Tax extenders are loathed by tax experts of all stripes, but Congress likes it for both lawmaking and political fundraising purposes.

Back in 2015, Congress passed what it vowed was the last tax extender package. Most of that was just talk, but there was some truth to it. The big-ticket extender items were made permanent, taking a lot of air out of the extenders balloon ever since. In addition, the solar power industry (as well as some other “green” tax credit beneficiaries) committed to a glidepath to wean themselves off of the need for tax benefit support.